A writing or drawing board of the type described is already known, being disclosed in German patent specification No. 1,611,811, for example. The clamp bar has a clamping part which rests on, or above, the clamping surface when in the clamping position, and a grip which extends beyond the clamping surface. If the grip is pressed downwards, the clamping part is lifted off the magnetized clamping surface. After it is released, the clamp bar is attracted by the magnetized clamping surface and firmly holds the sheet inserted between that surface and the clamp bar. While the sheet is being introduced between the clamping surface and the clamp bar, the latter must be retained in the release position by hand, until the sheet has been accurately aligned in the position in which it is to be clamped.
An object of the present invention is to provide a writing or drawing board of the type described, in which the clamp bar can be retained by simple means in its release position, without being held by hand, so that a sheet can be easily introduced without obstacle between the clamp bar and the clamping surface and aligned in that position.